Experimental studies on neutronics of coupled grooved liquid-hydrogen moderator for long pulse spallation sources

The development of technology for aircraft and rocket engines more efficient and environmentally friendly cryogenic fuels in the form of liquefied gases: hydrogen (vinyl), oxygen (oxide), natural gas (methane), required the creation of pipelines from modern composite materials, as well as new thermal insulation coatings (TIC), providing reliable protection of these highways from external heat leakage. Fuel out-of-flight manifolds of reusable aircraft require a particularly reliable TIC, since during the operation of the product, their multi-cycle cooling down occurs when pouring cryogenic fuel into the pipelines and heating at the discharge. Thermally insulating coatings in the form of polyurethane foam (PUF), applied to the surface of the protected product, by spraying or pouring a mixture of the constituent components, which are widely used at the present time, are not fully suitable for cryogenic pipelines due to the deterioration of their heat insulating properties in the process of cyclic cooling. The aim of the work is to create a new design and technological solution that ensures the performance of the TIC in the conditions of high-cycle thermal loading. In connection with the prospect of using cryogenic fuels in an aviation (reusable) technology, ensuring the performance of a TIC in such conditions is relevant. For the developed technology, experimental determination of the main parameters of the TIC was carried out. Composite pipelines of curvilinear and rectilinear shape were used as objects of research. The pipeline design included a sealing film sheath, a power sheath made of a polymer composite material, a foam heat insulating coating and metal connecting flanges. On model composite samples of cryogenic pipelines, cyclic tests for cooling with liquid hydrogen (filling of fuel lines) and heating to ambient temperature (draining components) were carried out. During the tests, the pipeline was first cooled with hydrogen gas for one hour. Then, for one hour, liquid hydrogen was poured into the internal cavity, after which natural warming up to a normal temperature was carried out for an hour. The obtained results allowed to determine the dependence of temperature and heat flow of the shell with TIC on the number of cooling cycles, to propose a design and technological solution for a significant reduction of the cryopump at large temperature differences in the TIC, to show the effectiveness of cyclic cooling of foam porosity with closed porosity of the “Vikort-3M”

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Experimental Study on the Damage of Optical Materials by out of Band Composite Laser

Applied Sciences ◽

10.3390/app10103578 ◽

2020 ◽

Vol 10 (10) ◽

pp. 3578 ◽

Cited By ~ 1

Author(s):

Liu Yang ◽

Liu Lisheng ◽

Tang Wei ◽

Shao Junfeng ◽

Li Xuelei ◽

...

Keyword(s):

Pulse Laser ◽

Experimental Studies ◽

Damage Threshold ◽

High Energy ◽

Experimental Results ◽

Laser Damage ◽

Energy Laser ◽

High Energy Laser ◽

Long Pulse ◽

Composite Laser

For the paper, experimental studies were performed on the damage of the Ge- and Si-based flat window by lasers out-of-band. The experimental results showed that lasers out-of-band can cause film damage and substrate damage to Ge and Si windows. The high-energy laser damage window mechanism mainly manifested as thermal effects. The composite laser damage thresholds for the substrate were an Si window of 21.6 J/cm2 and a Ge window of 3 J/cm2. Compared with continuous laser and long pulse laser experimental results, it was found that the use of long pulse-continuous composite constitution could effectively reduce the damage threshold. Compared to the long-pulse laser, the composite laser could achieve similar damage effects with a smaller energy density.

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Experimental studies towards long pulse steady state operation in LHD

Nuclear Fusion ◽

10.1088/0029-5515/41/6/314 ◽

2001 ◽

Vol 41 (6) ◽

pp. 779-790 ◽

Cited By ~ 16

Author(s):

N Noda ◽

Y Nakamura ◽

Y Takeiri ◽

T Mutoh ◽

R Kumazawa ◽

...

Keyword(s):

Steady State ◽

Experimental Studies ◽

Steady State Operation ◽

Long Pulse

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Experimental Studies of Decay and Formation of Capillary Turbulence on the Surface of Liquid Hydrogen

10.1063/1.2354671 ◽

2006 ◽

Author(s):

M. Yu. Brazhnikov ◽

G. V. Kolmakov ◽

A. A. Levchenko ◽

L. P. Mezhov-Deglin

Keyword(s):

Experimental Studies ◽

Liquid Hydrogen ◽

Capillary Turbulence

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3-D reconstruction and analysis of mammalian mitotic spindle structure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123295 ◽

1992 ◽

Vol 50 (1) ◽

pp. 578-579

Author(s):

Kent McDonald ◽

David Mastronarde ◽

Rubai Ding ◽

Eileen O'Toole ◽

J. Richard McIntosh

Keyword(s):

Cross Sections ◽

Mitotic Spindle ◽

Experimental Studies ◽

Video Camera ◽

Three Dimensions ◽

Mitotic Spindles ◽

Black And White ◽

Reconstruction Methods ◽

Spindle Structure ◽

Tissue Culture Line

Mammalian spindles are generally large and may contain over a thousand microtubules (MTs). For this reason they are difficult to reconstruct in three dimensions and many researchers have chosen to study the smaller and simpler spindles of lower eukaryotes. Nevertheless, the mammalian spindle is used for many experimental studies and it would be useful to know its detailed structure.We have been using serial cross sections and computer reconstruction methods to analyze MT distributions in mitotic spindles of PtK cells, a mammalian tissue culture line. Images from EM negatives are digtized on a light box by a Dage MTI video camera containing a black and white Saticon tube. The signal is digitized by a Parallax 1280 graphics device in a MicroVax III computer. Microtubules are digitized at a magnification such that each is 10-12 pixels in diameter.

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